The field of the invention relates generally to multiphase pumping systems and, more particularly, to systems and methods for controlling the gas volume fraction (GVF) of the fluid transported by the multiphase pumping systems.
As oil and gas fields in shallow waters diminish, producers are tapping offshore fields in deeper waters with oil installations that operate far below the surface of the sea. Typical production equipment and systems for such subsea oil recovery and production include a multiphase pump located in a subsea boosting station which pumps the oil from a well head up a pipeline riser to topside production equipment. The output of an offshore field, received from the well head and at the subsea boosting station, typically includes a combination of hydrocarbon oil, hydrocarbon gas, and water. These production components form production fluids having varying GVF. The multiphase pump is generally designed to operate with the production fluids having relatively low GVF. However, gas slugs may occur due to flow instability of multiple phases of the production fluids when gas separates from a mixed flow to form bubbles. Eventually, these gas slugs may enter the fluid processing system and may cause rapid variations of the GVF to higher values.
These slugs and the resulting higher values of GVF within the fluid may exceed the operating parameters of the multiphase pump, and if allowed to reach the multiphase pump, such slugs and higher values of GVF may contribute to a reduction in the service life of the multiphase pump.